3 Answers
3

You may be looking for WordNet, a lexical database for English developed by Princeton's Computer Science department. It has a permissive license allowing free use even in commercial applications. However, WordNet does not have “closed-class” words, including pronouns, prepositions, conjunctions, determiners, and particles.

I agree that WordNet is a pretty good source for definitions. I have started to build a multilingual dictionary (Deect) on top of WordNet's English words and definitions (actually included a few more things), and the users usually like the definitions from WordNet.

I would be great if you would release the project as open source, would you consider creating an organization on github? I would be willing to contribute, clean data, help maintain it etc.
–
opensourcechrisJul 25 at 12:28